What is the best scraper to use for my aquarium?

I have a 29 gallon saltwater fish tank, and I have a glass magnet already, but that is not certain algae get pink and green out of the cup. What is the best yardstick to use to clean the glass?

If it's a tank glass razor blade is best. If the acrylic, use a credit card or identity card or something similar. Cheap and easy, and really are the best methods!

Magnetic aquarium cleaner

Algae Free Piranha Float Algae Magnet $43.99 …

Floating Aquarium Magnet Super Acrylic Glass (Catalog Category: Aquarium / Maintenance Equipment) Floating Aquarium Magnet Super Acrylic Glass. MagFloatGulfstream Tropical Aquarium – Float1000 SuperProfessional SizeMagFloat: Floating magnetic aquarium glassacrylic cleaner. Recommended for aquarium surfaces ranging from 1 1/2 to 2…